Electronic systems that may use digital and/or analog circuits, such as microprocessors, for example, generally operate when supplied with a supply voltage. Many electronic systems are designed to operate from supply voltages that are regulated to provide a voltage that is within a range of voltage suitable for the circuitry.
Voltage regulators may generally include devices that have an input coupled to a power source and an output coupled to a load. In operation, a voltage regulator may draw energy from the power source and deliver energy to the load at a regulated voltage. Generally, the voltages of the power source and the load may be substantially independent of each other, an the voltage may be substantially different. In normal operation, the voltage regulator operates to supply current to the load at a voltage within an operating range of a nominal voltage. Some voltage regulators may be specified to regulate the voltage supplied to the load to within a tolerance of, for example, 1%, 5%, or 10% of the nominal voltage.
The nominal voltage that the regulator supplies to the load may depend on the type of load being supplied. In some digital systems, a voltage regulator may supply a nominal voltage of, for example, 3.3 Volts or 5 Volts. In some analog systems, a voltage regulator may supply a nominal voltage of, for example, −5 Volts, 2.5 Volts, 5 Volts, or 12 Volts. Many other tolerances and/or nominal voltages are possible.
Voltage regulators may be of various designs. For example, some switched mode dc-to-dc converters may produce a regulated output voltage by rapidly storing and releasing energy into and out of an energy storage element (e.g., inductor, capacitor). Examples of some switched-mode voltage regulator topologies include charge pumps, boost, buck, buck-boost, flyback, SEPIC, Cuk, and forward converters. Another type of voltage regulator is a linear regulator. Examples of linear regulators may include series pass and shunt regulators.